ALBERT

Description: Numerous newly-identified traces of active faults in the Himalayan foothill zone along the HFF around Chandigarh, in Pinjore Dun, along the piedmont zone of the Lower Siwalik hill front and within the Lower Tertiary hill range reveal the pattern of thrust and strike-slip faulting, striking parallel to the principal structural trend (NNW-SSE) of the orogenic belt. The active Chandigarh Fault, Pinjore Garden Fault and Barsar thrust have vertically dislocated, warped and backtilted fluvial and alluvial-fan surfaces made up of Late Pleistocene-Holocene sediments. West- and southwest-facing fault scarplets with heights ranging from 12 to 50 m along these faults suggest continued tectonic movement through Late Pleistocene to recent times. Gentle warping and backtilting of the terraces on the hanging wall sides of the faults indicate fault-bend folding. These active faults are the manifestation of north-dipping imbricated thrust faults branching out from the major fault systems like the Main Boundary Fault (MBF) and Himalayan Frontal Fault (HFF), probably merging down northward into a décollement. The Taksal Fault, striking NNW-SSE, shows prominent right-lateral movement marked by lateral offset of streams and younger Quaternary terraces and occupies a narrow deep linear valley along the fault trace. Right stepping along this fault has resulted in formation of a small pull-apart basin. Fault scarplets facing ENE and WSW are the manifestation of dip-slip movement. This fault is an example of slip-partitioning between the strike-slip and thrust faults, suggesting ongoing oblique convergence of the Indian plate and northward migration of a tectonic sliver. Slip rate along the Taksal Fault has been calculated as 2.8 mm/yr. Preliminary trench investigation at the base of the Chandigarh Fault Scarp has revealed total displacement of 3.5 m along a low angle thrust fault with variable dip of 20° to 46° due northeast, possibly the result of one large magnitude (Mw 7) prehistoric earthquake. Taking into consideration the height of the Pinjore surface (20 to 25 m), tentative age (8.9 ± 1.9 ka), displacement during one event and average angle of fault dip (25°) gives slip rate of about 6.3 ± 2 mm/yr, a rate of horizontal shortening of 5.8 ± 1.8 mm/yr and recurrence of faulting of 555 ± 118 years along the Himalayan Frontal Fault.

Description: Published

Description: JCR Journal

Description: open

Description: Turrialba Volcano, located in Central-Southern Costa Rica, has been characterized, since the last period of eruptive activity in 1884-1886, by a weak and discontinuous fumarolic activity in the western area of its summit. During the 1998-2002 period, fumaroles discharging from central and West craters were collected for chemical analyses of major and trace gas compounds, 13C/12C in CO2 and 18O/16O and D/H (in one fumarolic condensate), isotopic ratios. Geophysical measurements (seismic activity and ground deformation), monitored in the same period, were compared to geochemical data to define the status of the volcanic system. Chemical and isotopic characteristics of fumaroles of Turrialba Volcano seem to be related to interaction processes between a magmatic source and a shallower hydrothermal aquifer. Since February 1997, seismicity at Turrialba Volcano gradually increased, while since August 2001 new fumaroles start to discharge from a new fracture system located in the area between central and West craters. Since September 2001, strong compositional changes of gas discharges have been recorded at central crater. These occurrences are possibly due to variations in the permeability of the conduit system feeding the fumaroles. Heat pulse episodes from a magmatic source have possibly caused the increase of vapour pressure at depth and, consequently, favoured the uprising of the magmatic fluids toward the surface. The observed evolution of chemical and physical parameters suggests that to forecast a possible renewal of the volcanic activity in the near future a full program of both geochemical and geophysical surveillance must be provided at Turrialba Volcano.

Description: Published

Description: JCR Journal

Description: open

Description: A sudden increase in the scale of seismicity has occurred as a long-term precursor to twelve major earthquakes in California and Northern Mexico. These include all earthquakes along the San Andreas system during 1960-2000 with magnitude M 6.4. The full list is as follows: Colorado Delta, 1966, M 6.3; Borrego Mt., 1968, M 6.5; San Fernando, 1971, M 6.6; Brawley, 1979, M 6.4; Mexicali, 1980, M 6.1; Coalinga, 1983, M 6.7; Superstition Hills, 1987, M 6.6; Loma Prieta, 1989, M 7.0; Joshua Tree, 1992, M 6.1; Landers, 1992, M 7.3; Northridge, 1994, M 6.6; Hector Mine, 1999, M 7.1. Such a Precursory Scale Increase () was inferred from the modelling of long-term seismogenesis as a three-stage faulting process against a background of self-organised criticality. The location, onset-time and level of are predictive of the location, time and magnitude of the future earthquake. Precursory swarms, which occur widely in subduction regions, are a special form of ; the more general form is here shownto occur frequently in a region of continental transform. Other seismicity precursors, including quiescence and foreshocks, contribute to or modulate the increased seismicity that characterises . The area occupied by is small compared with those occupied by the seismicity precursors known as AMR, M8 and LURR. Further work is needed to formulate as a testable hypothesis, and to carry out the appropriate forecasting tests.

Description: Published

Description: JCR Journal

Description: open

Description: On 3rd November 2002, at about 3 km off-shore of Panarea Island (Aeolian Islands, Southern Italy), a series of gas vents suddenly and violently opened from the seafloor at the depth of 10-15 m, with an unusually high gas flux and superimposing on the already existing submarine fumarolic field. Starting from the 12th November 2002 a discontinuous geochemical monitoring program was carried out. The emissions consisted in an emulsion whose liquid phase derived from condensation of an uprising vapor phase occurring close to the fluid outlets without significant contamination by seawater. The whole composition of the fluids was basically H2O- and CO2-dominated, with minor amounts of typical «hydrothermal» components (such as H2S, H2, CO and light hydrocarbons), atmospheric-related compounds, and characterized by the occurrence of a significant magmatic gas fraction (mostly represented by SO2, HCl and HF). According to the observed temporal variability of the fluid compositions, between November and December 2002 the hydrothermal feeding system was controlled by oxidizing conditions due to the input of magmatic gases. The magmatic degassing phenomena showed a transient nature, as testified by the almost complete disappearance of the magmatic markers in a couple of months and by the restoration, since January 2003, of the chemical features of the existing hydrothermal system. The most striking feature of the evolution of the «Panarea degassing event» was the relatively rapid restoration of the typical reducing conditions of a stationary hydrothermal system, in which the FeO/Fe1.5O redox pair of the rock mineral phases has turned to be the dominating redox controlling system.

Description: Published

Description: JCR Journal

Description: open

Description: We present here the results of a five-years-long earthquake educational project aiming to commemorate the hundredth anniversaries of five large Northern Apennines earthquakes occurred between 1916 and 1920 in the areas of: Rimini (1916, Mw 6.1), Valtiberina (1917, Mw 5.9), Romagna Apennines (1918, Mw 5.9), Mugello (1919, Mw 6.3) and Garfagnana (1920, Mw 6.5) earthquakes. We saw these anniversaries as the occasion for leading the Northern Apennines people to rediscover their past, in a positive way, and to improve their awareness of the earthquake as a natural feature of the regions in which they live. The activities that we planned for schools students encouraged them to go hunting for traces of the earthquakes of one hundred years ago in their home towns and to rediscover the memories and traditions of their communities. Together with their teachers, we also led the teenagers to find creative ways to involve the grownups in the process of discovery and knowledge. The Project had to cope with two emergencies: the great Central Italy earthquake of 2016-2017 and the Covid-19 epidemic. However, these stumbling blocks did not deter teachers and students from taking part in the process actively and even enthusiastically. Their families and communities were actively involved too. This experience taught us some valuable lessons. First of all, we learned to adapt the project, as we had conceived it at the start, to a wide gamma of social and cultural contexts. Not all the involved communities were equally aware of the level of seismic risk they are exposed to. On the affluent Adriatic coast, where tourism is the main source of income, past earthquakes are something best forgotten, by citizens and administrators alike. On the contrary, in the poorer inland mountain areas (Forlivese Apennines, Mugello, Garfagnana and Lunigiana) a more down-to-earth attitude prevails: earthquakes are looked upon as something that can and does happen and people are quick to grasp how important it is to contribute to initiatives whose aim is reducing seismic risk. Thus, we had to adapt our approach to the different contexts, modifying each time the activities we proposed to the schools with the aim of obtain the best possible results from each situation. Presentiamo i risultati di un progetto di educazione al rischio sismico attivato in occasione dei centenari di cinque terremoti storici che hanno colpito l’Appennino settentrionale tra gli anni 1916 e 1920 e precisamente i terremoti di Rimini 1916 (Mw 6.1), Valtiberina 1917 (Mw 5.9), Appennino romagnolo 1918 (Mw 5.9), Mugello 1919 (Mw 6.3) e Garfagnana 1920 (Mw 6.5). Abbiamo pensato di utilizzare questi anniversari come punto di partenza per accompagnare i cittadini a riappropriarsi del loro passato in modo positivo, facendo crescere la loro consapevolezza del terremoto come un carattere del loro ambiente naturale. A tal fine, nelle attività realizzate con le scuole, abbiamo incoraggiato gli studenti a cercare le tracce dei terremoti di un secolo fa nell’ambiente urbanizzato e a indagare le memorie e le tradizioni ancora presenti nelle comunità. Insieme ai loro insegnanti abbiamo spinto i ragazzi a trovare modi creativi per coinvolgere gli adulti in questo processo di scoperta e conoscenza. Il progetto è stato messo alla prova dal forte terremoto dell’Italia centrale (2016­2017) e dall’epidemia di Covid­19, ma nonostante queste difficoltà insegnanti e studenti hanno partecipato con grande interesse a questo percorso e hanno coinvolto nelle attività del progetto le famiglie e le comunità locali. Anche noi abbiamo imparato nuove lezioni. Un aspetto importante che abbiamo appreso è il bisogno di adattare il progetto a contesti sociali e culturali che si sono rivelati molto diversi. Le comunità coinvolte non condividono lo stesso livello di consapevolezza del rischio: sulla costa adriatica, a vocazione turistica, i terremoti sono qualcosa che è meglio dimenticare, sia da parte dei cittadini che dalle amministrazioni. Al contrario, nell’Appennino forlivese, nel Mugello, in Garfagnana e Lunigiana, i terremoti sono una presenza costante e le persone si sono sentite subito coinvolte in un processo attivo di riduzione del rischio e di attenzione quotidiana. Questo ci ha spinto ad adattare ogni volta l’approccio ai diversi contesti, modificando le proposte di attività che abbiamo realizzato nelle scuole.

Description: Lavoro realizzato nell’ambito della Convenzione fra INGV e Dipartimento della Protezione Civile, Allegato A, tematica “M”.

Description: Published

Description: 1-40

Description: 5SR TERREMOTI - Convenzioni derivanti dall'Accordo Quadro decennale INGV-DPC

Description: JCR Journal

Description: The Global Navigation Satellite System (GNSS) represents a primary data source in Solid Earth Sciences. In order to investigate the Earth’s crustal deformation, time series of the estimated daily positions of the stations are routinely analyzed at the Istituto Nazionale di Geofisica e Vulcanologia (INGV) to investigate the deformation of the Earth’s surface caused by tectonic and non-tectonic processes. The GNSS observations of the stations are processed using the three main scientific software: GAMIT/GLOBK, BERNESE, and GIPSY OASIS II. The accuracy and the strength of geodetic solutions often depend on the geometry and spatial density of the network, and the availability and quality of GNSS data. In many circumstances, GNSS networks are deployed for topographic purposes by private or public institutions, and a significant number of GNSS stations in large regions acquire continuous observations. It may happen that such networks do not collect and distribute data according to IGS standards, so it could be difficult to analyze this data using automated data-processing tools. For that reason, this data is often ignored or partially used by the scientific community, despite their potential usefulness in geodynamic studies. We have attempted troubleshooting this problem by establishing a centralized storage facility in order to collect all available GNSS data and standardize both formats and metadata information. Here we describe the processes and functions that manage this unified repository, called MGA (Mediterranean GNSS Archive), which regularly collects GNSS RINEX files from alarge number of CORS (Continuously Operating Reference Station) located across a wide region of mainly the European and African plates. RINEX observation data and metadata information are provided to the analysts through an FTP server and dedicated web-services. The complete data set is stored in a PostgreSQL database in order to easily retrieve pieces of information and efficiently manage the archive content. The system implements many high-level services that include scripts to download files from remote archives and to detect new available data, web applications such as API (Application Program Interface) to interact with the system, and background services that interact with the database. During the development of this product, particular attention was paid to what has already been achieved by EPOS TCS WP10, whose objective was: "[...] to develop an open source platform with programmatic and web interfaces to store and disseminate raw data and metadata from GNSS stations operating in Europe''. Many ideas and tools presented here were inspired by that project.

Description: Published

Description: 1-18

Description: 2T. Deformazione crostale attiva

Description: 1IT. Reti di monitoraggio e sorveglianza

Description: 4IT. Banche dati

Description: N/A or not JCR

Description: SISMIKO è uno dei Gruppi Operativi di emergenza sismica dell’Istituto Nazionale di Geofisica e Vulcanologia (INGV) con la principale missione di installare, nel più breve tempo possibile, una rete sismica temporanea in tempo reale ad integrazione di quella permanente nell’area colpita da un forte terremoto e/o da una sequenza sismica [Moretti et al., 2012; 2016]. SISMIKO nasce formalmente nel 2015 ed è il frutto della convergenza di reti sismiche mobili gestite da diversi gruppi all’interno delle singole Sezioni e sedi dell’Ente. Ognuna di queste reti risente della propria storia, risponde ad esigenze territoriali diverse ed è caratterizzata da vari gradi di coinvolgimento nella gestione della Rete Sismica Nazionale (RSN) [Michelini et al., 2016; Margheriti et al., 2020]. Questa eterogeneità si riflette anche in differenze nel sistema di acquisizione dati delle stazioni gestite dal GO. Grazie ad una attenta predisposizione e configurazione della propria strumentazione, oggi SISMIKO ha la possibilità e le competenze per integrare in poche ore una rete temporanea trasmessa in tempo reale nel sistema di acquisizione dati sismologici attivo presso la sede INGV di Roma, contribuendo in maniera significativa al servizio di monitoraggio e sorveglianza sismica del territorio colpito dall’emergenza [Margheriti et al., 2020]. Nel corso del 2020, facendo seguito al piano di rinnovo e omogeneizzazione del parco strumentale dedicato GO avviato nel 2019 (co­finanziato nell’ambito della Convenzione tra INGV e il Dipartimento di Protezione Civile vigente), è stato deciso di sviluppare un sistema di acquisizione dati in tempo reale unificato per tutte le stazioni di SISMIKO, indipendente dalle singole sedi di appartenenza. Questa nuova logica ha diversi vantaggi, e in primis quello di rendere possibile il completo interscambio del personale presso le varie sedi INGV nella gestione dell’acquisizione dati, aspetto fondamentale durante una emergenza.

Description: Published

Description: 1-26

Description: 2SR TERREMOTI - Gestione delle emergenze sismiche e da maremoto

Description: N/A or not JCR

Description: In Italy, historical research on earthquakes has a long and glorious tradition, which in recent decades has gone through very different phases. In the first half of the 1980s and up to the mid- 90s, two very demanding research ventures were developed: the research program financed by ENEL for the qualification of sites susceptible to nuclear plants in three areas of the country (Piedmont, Lombardy, Puglia), later merged into the “Catalog of Strong Italian Earthquakes” (CFTI) of the ING/INGV, and the “Hazard project” of the GNDT/CNR, aimed at preparing all the basic data necessary for a model of hazard updated. As part of these two ventures, for about a decade over a hundred researchers, mostly “professional” historians, have worked to update their knowledge of Italian historical earthquakes. Researches developed by the “Hazard Project” - complementary to those of the CFTI - aimed only at rapidly re-evaluating the knowledge on about 600 intermediate energy earthquakes. Some of these studies, after a couple of decades, are now largely obsolete. For this reason, a work plan was launched aimed at deepening the knowledge on several dozens of these studies, marked in the current Parametric Catalog of Italian Earthquakes (CPTI15) by the initials AMGNDT95, providing them with an updated and, hopefully, better database. This work presents the results of research carried out on 6 earthquakes included in the 1949– 1971 time span. Such researches have allowed a significant improvement of the epicentral parameters of these earthquakes and, at the same time, an enhancement of seismic histories of numerous localities.

Description: Lavoro realizzato nell’ambito della Convenzione fra INGV e Dipartimento nazionale della Protezione Civile, Allegato B2.

Description: Published

Description: 1-274

Description: 4T. Sismicità dell'Italia

Description: JCR Journal

Description: In recent decades, geological modeling has significantly evolved, relying on the growing potential of hardware and software to manage and integrate vast datasets of 2D-3D geophysical underground data. Therefore, digitization and integration with other forms of data can often improve understanding of geological systems, even when using so-called vintage or historical data. Seismic reflection data have been extensively acquired mainly for hydrocarbon exploration since the 60s generating large volumes of data. Typically, these data have been for private commercial use and are relatively unavailable for research. However, with time, large volumes of vintage seismic reflection data in many countries worldwide are now becoming publicly available through time-based de-classification schemes. Such data have a great potential for modern-day geo-research, unleashing opportunities to improve geological understanding through re-interpretation with modern methods. However, a downside of these vintage data is that they are often only available in analog (paper, raster) format. The vectorization of these data then constitutes an essential step for unlocking their research potential. In 2018 INGV established the SISMOLAB-3D infrastructure, which is mainly devoted to analyzing digital subsurface data, such as seismic reflection profiles and well-logs, to build 2D-3D geological models, principally for seismotectonics, seismic hazard assessment, and geo-resources applications. In this contribution, we discuss the robustness of the WIGGLE2SEGY code, firstly published by Sopher in 2018, focusing on examples from different tectonic and geodynamic contexts within Italian territory. We applied the SEG-Y conversion method to onshore and offshore raster seismic profiles related to ceased exploration permits, comparing the results with other published archives of SEG-Y data obtained from the conversion of vintage data. Such an approach results in digital SEG-Y files with unprecedented quality and detail. The systematic application of this method will allow the construction of a comprehensive dataset of digital SEG-Y seismic profiles across Italy, thereby expanding and sharing the INGV SISMOLAB-3D portfolio with the scientific community to foster innovative and advanced scientific analysis.

Description: Published

Description: DM538

Description: 1TR. Georisorse

Description: 2TR. Ricostruzione e modellazione della struttura crostale

Description: 2IT. Laboratori analitici e sperimentali

Description: JCR Journal

Description: Probabilistic volcanic hazard assessment is a standard methodology based on running a deterministic hazard quantification tool multiple times to explore the full range of uncertainty in the input parameters and boundary conditions, in order to probabilistically quantify the variability of outputs accounting for such uncertainties. Nowadays, different volcanic hazards are quantified by means of this approach. Among these, volcanic gas emission is particularly relevant given the threat posed to human health if concentrations and exposure times exceed certain thresholds. There are different types of gas emissions but two main scenarios can be recognized: hot buoyant gas emissions from fumaroles and the ground and dense gas emissions feeding density currents that can occur, e.g., in limnic eruptions. Simulation tools are available to model the evolution of critical gas concentrations over an area of interest. Moreover, in order to perform probabilistic hazard assessments of volcanic gases, simulations should account for the natural variability associated to aspects such as seasonal and daily wind conditions, localized or diffuse source locations, and gas fluxes. Here we present VIGIL (automatized probabilistic VolcanIc Gas dIspersion modeLling), a new Python tool designed for managing the entire simulation workflow involved in single and probabilistic applications of gas dispersion modelling. VIGIL is able to manage the whole process from meteorological data processing, needed to run gas dispersion in both the dilute and dense gas flow scenarios, to the post processing of models’ outputs. Two application examples are presented to show some of the modelling capabilities offered by VIGIL.

Description: Published

Description: DM107

Description: 6V. Pericolosità vulcanica e contributi alla stima del rischio

Description: JCR Journal